1. Field of the Invention
The present invention relates to a server, a terminal apparatus and an image management method that adds a water-mark to document data.
2. Description of Related Art
This application is based on the Japanese Patent Application No. 2002-379056 filed on Dec. 27, 2002, entire content of which is expressly incorporated by reference herein.
As noted in the present application, a water-mark means a word such as e.g. “confidential” or another indication that is utilized to keep document data secret or to indicate another restricted status of the document data.
Related Art Japanese Patent Laid Open Publication 2001-318771 (Page 4, left column) discloses a printer server that obtains a print job from a client apparatus. The client apparatus is connected to the same network as the printer server. The printer server requests a printer to perform the print job. After the printer server adds a water-mark such as “confidential” to document data that is transferred from the client apparatus, the printer server instructs a printer to print the document data with the water-mark.
In the related art, the print server analyzes a PDL data in the print job. When the printer server find a key word such as “customer” in a document name of the PDL data, the printer server judges that the PDL data is confidential. When the PDL data is confidential, the printer server takes information customized for a particular client, from the print job. The printer server converts the information into a PDL data and sets the converted PDL data as a water-mark. Then the printer server combines the PDL data of the document data with the PDL data of the water-mark. After that, the printer server requests the printer to print the document data with the water-mark based on the combined PDL data.
The print server can pre-store a PDL data of the water-mark and can add the PDL data of the water-mark to the PDL data of document data, instead of above information customized for a particular client.
However, the above described related art has the following problems.
The printer server combines the PDL data of the document data with the PDL data of the water-mark, and then the printer generates the document data with the water-mark based on the combined PDL data. Thus, the water-mark appears only on a printed paper. In the other words, when a client see an original image of the document data on a display section of a personal computer before the document data is printed out, the original image without the water-mark can appear on the display section of the personal computer. This means that the client can edit the original image and the client can transfer the original image without the water-mark to another user. Therefore, the related art can not maintain a secret status of the original image.
The related art requires a printer to have a capability of providing the water-mark. However, not all the printers have the capability of providing the water-mark. When a client uses a printer that does not have a capability of providing the water-mark, an original image that must be maintained in a secret status will be printed without the water-mark. Therefore, the related art can not protect a confidential document from being released to an inappropriate party.
As above described, the related art determines whether a document data is confidential or not, based on the document name of the PDL data. However, the document name is easily changed by anyone. If someone deliberately changes the document name, a confidential document can be printed out without the water-mark. Also before a client adds a water-mark to an image, the client has to know which document names the print server recognizes as keywords indicating confidentiality. If the client inputs a wrong key word, a confidential document will be printed out without the water-mark. Therefore, the related art can not protect a confidential document from being released to an inappropriate party.